.submit {
	width: 150px;
	height: 150px;
	display: block;
	margin: 50px auto;
	border-radius: 50%;
	box-shadow: 2px 2px 8px #2E9CFE;
	border: 0;
  background: -webkit-radial-gradient(#1578CA, #0977C4, #FFFFFF); /* Safari 5.1 - 6.0 */
  background: -o-radial-gradient(#1578CA, #0977C4, #FFFFFF); /* Opera 11.6 - 12.0 */
  background: -moz-radial-gradient(#1578CA, #0977C4, #FFFFFF); /* Firefox 3.6 - 15 */
  background: radial-gradient(#1578CA, #0977C4, #FFFFFF); /* 标准的语法 */
}